Excessive CYA leading to green pool?

[Shrek60]

Approximately 6 weeks ago I added CYA to my pool. I am not sure exactly how I did so, but I put to much CYA in the pool. Now the walls of the pool turn green about every 10 days, to the chagrin of my wife and grandchildren. I am sure the high CYA is hurting the effectiveness of the Chlorine. Here is my question. If I want to lower the CYA from 100 to 50, do I drain the pool 50%? Do I drain, test, drain, test until I hit my CYA mark? Here are the results of my latest test using a Taylor Test Kit. Thanks. Tony

FC - 6
pH - 7.2
TA - 100
CH - 0
CYA - 100
SALT - 3100
TEMP - 89

 

[Texas Splash]

If I want to lower the CYA from 100 to 50, do I drain the pool 50%?

Basically yes, as long as the CYA is actually about 100 and not higher. Be careful about the flooding and elevated water table in your area though (if applicable). Better safe than sorry. While not as efficient, you might do 25% exchanges as opposed to a 50% dump if your area got flooded.

 

[Shrek60]

Basically yes, as long as the CYA is actually about 100 and not higher. Be careful about the flooding and elevated water table in your area though (if applicable). Better safe than sorry. While not as efficient, you might do 25% exchanges as opposed to a 50% dump if your area got flooded.

Thanks for the input Texas. No issue with flooding where we are at in North Alabama. I think I will replace about 40% of the pool water and then retest. It is frustrating, but a lesson learned about adding CYA. Time to pitch the pump in the pool. Thanks ad God Bless. Tony

 

[PoolStored]

Here is some good reading -->Draining Pay attention to the NO DRAIN WATER EXCHANGE.

I put my input hose in the deep end, and put a sump pump in the shallow. I put a ball valve on the sump pump and using a 5 gallon pail, tested input and output, adjusted the valve to match input and output. Was able to maintain water level while exchanging water. Had to adjust valve a couple times, but worked great.

After doing it, and following TFP, I have a great pool. Inspiration --> TFP Clear - Let's see PICs!

I would also recommend reading:
ABCs of Pool Water Chemistry
FC/CYA Levels

After you replace water, you will need to SLAM the pool to get rid of Algae.
SLAM Process

 

[Shrek60]

Here is some good reading -->Draining Pay attention to the NO DRAIN WATER EXCHANGE.

I put my input hose in the deep end, and put a sump pump in the shallow. I put a ball valve on the sump pump and using a 5 gallon pail, tested input and output, adjusted the valve to match input and output. Was able to maintain water level while exchanging water. Had to adjust valve a couple times, but worked great.

After doing it, and following TFP, I have a great pool. Inspiration --> TFP Clear - Let's see PICs!

I would also recommend reading:
ABCs of Pool Water Chemistry
FC/CYA Levels

After you replace water, you will need to SLAM the pool to get rid of Algae.
SLAM Process

Thanks for the input PoolStored. I was not aware of this method to exchange the water. My wife was concerned draining the pool would disturb the pool usage over the Labor Day weekend. Using this method I can stop the exchange and restart it as needed. This is what TFP is all about. Tony

 

[jtpipkin]

you can also elevate the free chlorine to accommodate and hopefully rain and dilution will bring it down over time - just a thought

 

[Mdragger88]

It hasn’t been mentioned yet but you need to do the diluted cya test to be sure of your actual cya since you tested over 90ppm. This will ensure you drain/exchange enough water to get where u need to be. Performing a SLAM Process process with a cya above 60 takes a lot of liquid gold .
It is step 8

CYA - Cyanuric Acid Test

Cyanuric acid (CYA) is the chemical name for the product commonly called “pool water stabilizer” … Read more…

www.troublefreepool.com

 

[PoolStored]

Using this method I can stop the exchange and restart it as needed. This is what TFP is all about. Tony

If you read it again, you do not want to stop the process, as the water will mix. If it mixes, you will end up replacing more water. If water is cheap, would be ok, but not ideal.

 

[Shrek60]

It hasn’t been mentioned yet but you need to do the diluted cya test to be sure of your actual cya since you tested over 90ppm. This will ensure you drain/exchange enough water to get where u need to be. Performing a SLAM Process process with a cya above 60 takes a lot of liquid gold .
It is step 8

CYA - Cyanuric Acid Test

Cyanuric acid (CYA) is the chemical name for the product commonly called “pool water stabilizer” … Read more…

www.troublefreepool.com

Mdragger thanks for the info. I completed the diluted test and it shows a reading of 90 CYA. I will do a water exchange. Thanks goodness water is inexpensive in our area. Tony

 

[Newdude]

Hey Shrek !! The folks above will have your swamp ship shape in no time.

I was not aware of this method to exchange the water. My wife was concerned draining the pool would disturb the pool usage over the Labor Day weekend. Using this method I can stop the exchange and restart it as needed

Just wanted to point out the no drain water exchange relies on the water being undisturbed. You will add from one end and drain from the other and the 2 will mostly stay separate. If you stop and begin again later after mixing it up, you will be draining an even % of however much you filled with the new water. It not the end of the world but it’s closer to doing multiple drains where each round becomes less efficient as you remove more and more good water.

I have something else to consider. Each year at closing I drained 18 inches and me/kids took one last swim to say goodbye. Those cannonballs were epic with another foot and a half to hit the water. Every last jump hit different as it was a totally different pool. (No diving of course as you’ll have less water). If you time the big drain right, you can swim all afternoon in slightly less water, finish draining until bedtime, then fill overnight and be plenty full to swim again in most of the water as it finishes.